Department of Entomology
A GUIDE ON THE USE OF PICS BAGS FOR GRAIN STORAGE
D. Baributsa1, I. Baoua2, T. Abdoulaye3, and L. Murdock1
1Department of Entomology, Purdue University, West Lafayette, IN, USA;
2Universite de Maradi, Maradi, Niger;
3International Institute of Tropical Agriculture, Nigeria
Post-harvest storage losses of grain to insects are at least
30% in Sub-Saharan Africa. There are many control methods but
most are minimally effective, expensive, not scalable, or present
The Purdue Improved Crop Storage (PICS) technology, a
triple layer bag composed of two polyethylene bags and one outer
woven polypropylene bag, minimizes insect storage losses. The
PICS bag works like other hermetic containers, by limiting the
supply of oxygen to insects living in stored grain. After PICS bags
are closed, insects in stored grain use up much of the oxygen left
inside the bag. When oxygen becomes too low, the insects cease
feeding, and stop growing and reproducing; this prevents serious
damage to the grain.
PICS bags were originally developed for cowpeas but later
shown to be effective against pests of several other stored crops
including maize, beans, sorghum, pigeon pea, peanuts, and rice.
A major effort to disseminate PICS bags in West and Central Africa
began in 2007.Work has since been expanded to East and Southern
Africa as well as Asia. By June 2015, more than 5 million bags had
been produced and sold by manufacturers and vendors to small-
holder farmers and other users. PICS training has reached millions
of farmers in more than 37,000 villages in Sub-Sahara Africa.
The PICS initiative aims to reduce post-harvest losses through
the use of hermetic storage methods; PICS bags being the main
driver. The instructions outlined here will serve as a guide for exten-
sion agents while implementing PICS activities. It describes steps in
using PICS bags, key recommendations, and questions frequently
asked by farmers.
Use of PICS bag - Procedure
The triple layer bag consists of two high density inner polyeth-
ylene plastic bags (inner liners) and a third outer sack (a woven
polypropylene bag). PICS bags should be handled carefully to
prolong their use and effectiveness.
Buy PICS bags from recognized
Make sure the bags being sold are
genuine, not counterfeits.
The bag should have the PICS lo-
gos displayed on both sides of the
The two inner liners should be thick
and fairly opaque.
Store only dry and clean grain that
contains no debris.
This will minimize damage to the
inner liner which could diminish ef-
Drying the grain adequately before
storage may help reduce the infes-
tation, maintain seed viability, and
minimize mold growth.
Separate the three
Check the integrity
of the two inner
liners for holes and
A PICS extension training.
Assess whether the bottom of both liners are well sealed.
Don’t use PICS bags with holes; they will be less effective.
A Guide on the Use of PICS Bags — E-265-W
READ AND FOLLOW ALL LABEL INSTRUCTIONS. THIS INCLUDES DIRECTIONS FOR USE, PRECAUTIONARY STATEMENTS (HAZARDS TO HUMANS, DOMESTIC ANIMALS, AND ENDANGERED
SPECIES), ENVIRONMENTAL HAZARDS, RATES OF APPLICATION, NUMBER OF APPLICATIONS, REENTRY INTERVALS, HARVEST RESTRICTIONS, STORAGE AND DISPOSAL, AND ANY SPECIFIC
WARNINGS AND/OR PRECAUTIONS FOR SAFE HANDLING OF THE PESTICIDE.
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Ø Store PICS bags away from sunlight or extreme heat.
Exposing bags to sunlight for long periods of time may damage
the woven bag and reduce its durability/usefulness.
Ø Store PICS bags on an elevated platform and away from walls
to facilitate inspection and minimize rodent attacks.
Ø Inspect PICS bags at least once a month.
Ø Keep PICS bag sealed at all times during grain storage. If grain
must be removed for home use or sale, ensure that excess air
is pressed out and the bag is resealed.
PICS technology is
Ø Easy to use, effective and no need to apply insecticides.
Ø Increases income and improves food security.
Ø Safely stores seed and grain.
Ø Grain stored in PICS bags may command a premium over
grain stored with chemicals.
Questions frequently asked by farmers.
ØShould we add insecticides to the PICS bag to improve
No, there is no need to add insecticides.
ØCan PICS bags be opened to remove some grain?
Yes, but the bag should be closed and resealed right away
to avoid reinfestation or resurgence of the insect
ØØCan seeds stored in PICS bags germinate?
Yes, but grain should be dried below 13% before storage
to maintain viability.
ØØCan PICS bags be reused?
Yes, three seasons on average. Avoiding holes in the
liners increases bag longevity
ØØCan I store several commodities in a PICS bag?
Yes, put each type of grain into a single small bag and put
all bags into a PICS bags. Seed and grain for home
consumption can be stored this way.
ØØWhy are PICS bags not available in smaller size?
Larger PICS bags (100 or 50 kg) can store smaller
quantities of grain (e.g. 20 kg). In addition, the storage cost
per kg is lower with larger bags, saving money.
ØØCan I store grain in PICS bag for one year or more?
Yes, grain can be stored in PICS bags for a year or more.
There are reports of grain being stored in PICS bags for
2 years or more.
Storage after 4 to 6 months
Pour a small amount of grain into the
rst liner to allow it to be more easily
inserted into the second liner; then
put both liners into the woven sac.
Fold the lips of the three bags
together - from inside out.
Fill the inner bag with grain
while shaking gently to
eliminate pockets of air.
Make sure no grain gets
between the liners.
Ensure a lip remains at the top
for tying. Pack the grain tightly
to remove air.
Step 1: Gently twist
the lip of the most
inner liner, fold it over
Benets of using PICS Technology
Step 2: Tuck the
knot from the rst
liner inside and re-
peat for the
Step 3: Finally, tie
the woven bag. Be
sure to fold and tie